Test Review
The earth is made up of a great variety of rock of differing ages. Canada has
some of the oldest rock, at about four billion years old. Scientists believe that the
earth formed in layers. Over time, the denser materials settled in the earth's
centre to form the core, while the lighter materials, including gases, formed its
outer layers and atmosphere.
At the centre is the core, which has two layers: a solid inner core that is very hot
because it is under great pressure, and the liquid outer core. The surface layer,
or crust, of the earth is solid. The middle layer, the mantle, is not. The material
of the mantle, a type of melted rock called magma, is a hot, relatively dense and
slow-moving fluid.
What are Landforms?
Landforms are the topography, that is, the natural features, of the land's
surface. A landscape is an area's landforms together with its cover of
vegetation, water, ice, and rock. Landscape also includes the activities of humans
and other animals. Cities are often referred to as urban landscapes, while
agricultural areas are called rural landscapes.
Topography may be described using the following terms:
Elevation: is used to describe the height of a landform. It is measured from sea
level.
Relief: is the difference in elevation between points on the earth's surface.
Gradient: refers to the steepness of slopes.
Geology: refers to the types of rocks and history of those rocks.
Weathering is the decomposing of rocks, soils and their minerals through direct
contact with the air.
Erosion is displacement of solids (soil, mud, rock and other particles) usually by
the agents of currents such as, wind, water, or ice by downward or down-slope
movement in response to gravity or by living organisms (in the case of
bioerosion).
Deposition is the geological process whereby material is added to a landform.
This is the process by which wind and water create a deposit, through the laying
down of granular material that has been eroded and transported from another
geographical location.
Canada's Landform Regions
A region is an area that is defined on the basis of the presence or
absence of certain characteristics. Geographers look for common
characteristics or combinations of chracteristics.
Regions:
Canadian Shield
Appalachian Mountains
Western Cordillera
Innuitian Mountains
Arctic Lowlands
Interior Plains
Great Lakes Lowlands
Hudson Bay Lowlands
Cardinal Directions
In stating directions, it is common to use the terms North(N), South(S), East(E)
and West(W)
These are the four cardinal directions
These terms may also be used in 2 and 3 letter combinations – NW, NE, SE,
SSE and so on
These combinations are known as inter-cardinal directions
Compass Bearings
For more precision, it is necessary to state a direction using a compass bearing,
given as a number
Remember that North has a value of 0° and the numbers increase in a
clockwise direction – East is 90° and so on
Scale
If an object or drawing is made to scale, it means that its dimensions are
relative to each other
Its proportions are the same as the real thing
A scale is a representative fraction (1/87, 1/160, 1/25, 1/700 etc.) giving a size
relative to the original
An accurate map must be made consistently to one particular scale
A common scale used in Canadian maps is 1:50000
1 cm represents 50000 cm (or .5 km)
Worldwide Grid
Maps showing large areas typically show lines of longitude and latitude
Lines of longitude are called meridians
Lines of latitude are called parallels
They form a grid
A geographic coordinate system is a coordinate system that enables every
location on the Earth to be specified by a set of numbers or letters. The
coordinates are often chosen such that one of the numbers represents vertical
position, and two or three of the numbers represent horizontal position. A
common choice of coordinates is latitude, longitude and elevation.
DDD° MM' SS.S"
32° 18' 23.1" N 122° 36' 52.5" W
This is the most common format used to mark maps. It's also the most
cumbersome to work with. It's a lot like telling time…
There are sixty seconds in a minute (60" = 1') and
There are sixty minutes in a degree (60' = 1°).
Keeping in mind a few easy conversions between seconds and decimal minutes
will help when working with maps that use degrees, minutes and seconds.
15 seconds is one quarter of a minute or 0.25 minutes
30 seconds is one half of a minute or 0.5 minutes
45 seconds is three quarters of a minute or 0.75 minutes